I 15 over Sep County Road
GoodCascade County, Montana · 3M N Ulm · Structure no. I00015274+02691
- Built
- 1969
- 56 years old
- Condition
- Good
- inspected July 2024
- Type
- Slab
- Concrete Continuous
- Length
- 79 ft
- 3 main spans
- Daily traffic
- 3,145
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 15 over Sep County Road is a concrete continuous slab carrying I 15 over Sep County Road in Cascade County, Montana. It was built in 1969, so it is 56 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 3,145 vehicles a day, roughly 12% of them trucks, projected to reach 3,301 by 2043. The structure is 79 ft (24.1 m) long and 44 ft wide.
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 8 Very Good | No problems noted. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 15 over Sep County Road built?
It was built in 1969, making it 56 years old in 2025.
What condition is I 15 over Sep County Road in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2024.
How much traffic does I 15 over Sep County Road carry?
About 3,145 vehicles per day (2023 count), of which roughly 12% are trucks.
How long is I 15 over Sep County Road?
The structure is 79 ft (24.1 m) long with a longest span of 30 ft (9.1 m) and a deck 44 ft wide.
Who owns I 15 over Sep County Road?
It is owned by the State Highway Agency.